The middle embryonic germ layer lying between the ectoderm and the endoderm from which connectivetissue muscle bone and the urogenital and circulatory systems develop.
中胚层中间胚芽层，位于外胚层和内胚层之间，最终发育成结缔组织、肌肉、骨骼、泌尿系统及循环系统。
2
The middle embryonic germ layer, lying between the ectoderm and the endoderm, from which connectivetissue, muscle, bone, and the urogenital and circulatory systems develop.